Hub assembly with ratchet member movable in one direction

ABSTRACT

A ratchet mechanism of a hub assembly is located between the hub and the tubular portion, and includes a driving member which is movable linearly in the tubular portion. One side of the driving member has a cone-shaped first ratchet portion located axially and is composed of two triangular contact surfaces. A passive member is fixed in the hub and has a cone-shaped second ratchet portion which is engaged with the first ratchet portion. A returning member is located between the hub and the driving member. The passive member is fixed to the hub easily. By the triangular cone-shaped first and second ratchet portions, the contact are and the friction between the ratchet portions are reduced, and the engagement and disengagement is more quick and smooth.

FIELD OF THE INVENTION

The present invention relates to a hub assembly, and more particularly,to a hub assembly with one ratchet member movable in one direction, andthe engagement and disengagement between two ratchet members to be moresmooth and efficient.

BACKGROUND OF THE INVENTION

A conventional bicycle hub assembly generally includes a hub, an axle, arotatable unit and a gear disk so as to position the axle and to allowthe wheel to rotate. According to practical needs, a tubular portion anda derailleur device are equipped. The hub assembly can transmit torquein one direction or in two directions, the one-direction transmissionmeans that the hub rotates in the forward direction to move the bicyclemove forward, and the reverse direction cannot move the bicycle. Thetwo-direction transmission means that the hub can transmit torque inboth directions. The ratchet mechanism for the one-directiontransmission hub can be engaged in radial direction or in axialdirection. The radial engagement means that the hub includes teeth inthe radial direction and the teeth are engaged with radial ratchetblocks. The axial engagement means that the hub includes teeth in theaxial direction and the teeth are engaged with axial ratchet blocks.

When in action, the one-direction transmission ratchet device generatesa linear movement between the ratchet device and the hub so as togenerate a gap to disengage the ratchet device and the hub. Therefore,the hub cannot transmit torque. The linear movement between the ratchetdevice and the hub can be two-side linear movement and single-sidelinear movement.

Taiwan Patent No. 088117780 discloses an axle, a hub co-axiallyconnected with the axle, at last one bearing device which includes atleast two bearings located between the hub and the axle, so that the hubis rotatable relative to the axle. A rotor is rotatable about the axleand has at least gear connected to the rotor. A free wheel which islocated between the rotor and the hub, and has two plates and each platehas a toothed surface. The two toothed surfaces are pushes toward eachother by a tension device. The two plates are co-axial with the axle andlocated on a plane that is perpendicular to the axis of the axle whenthe wheel is in stopped status. The plates are kept to be inclinedrelative to the plane perpendicular to the axis of the axle. The twoplates are installed consecutively and a spring pushes the two platestoward each other.

Taiwan Utility Patent No. 096219278 discloses a collar made by metal andmultiple teeth are defined in an inner periphery of the collar. Theteeth extend axially. A ratchet block is made by magnetic material andincludes two end surfaces. The shape of the ratchet block is axially andslidably engaged with the teeth of the collar. One end surface has anannular teeth and a fly wheel has another annular teeth which is engagedwith the annular teeth of the end surface in one direction. A permanentmagnet is connected to the other end surface that does not have theannular teeth.

The hub of the first example includes an annular threaded portion on theright end thereof and the annular threaded portion has teeth which areengaged with one of the plates in radial direction and can be movedlinearly relative to the plate. The rotor has teeth which are engagedwith the other plate in radial direction, so that linear movements canbe made in two directions. The two respective facing surfaces of the twoplates have teeth engaged with each other. The annular threaded portion,the two plates and the spring are cooperated to form a free wheelmechanism. The two plates can be moved linearly in two directions. Whenthe pedals are treaded forward, the teeth between the two plates arepushed to each other to transmit torque. When the pedals are treadedbackward, the teeth between the two plates slide over each other, andthe sliding action is cooperated with the linear movement in twodirections, the two plates are separated from each other so that the hubis rotated without torque being output.

The hub of the second example has annular ratchet teeth on the inside ofthe fly wheel and the ratchet block facing the fly wheel has annularratchet teeth so as to be engaged with the end of the fly wheel. Theratchet block is attracted by the permanent magnet so as to be normallylocated in the collar. The ratchet block is moved linearly relative tothe collar. The annular ratchet teeth on the other side of the fly wheelare fixed so as to form the linear movement in one direction between theratchet block and the hub. This also achieves the purpose that the hubtransmits torque in only one direction.

However, the teeth in the two examples are composed of an inclinedsurface and a vertical surface. Therefore, the teeth have a pre-setheight and there is a difference in height between the next tooth.During the interactive linear movement between the plates or the ratchetblocks, the inclined surface is too large so that no gap is formed andthis causes wearing by friction between the teeth. The frictiongenerates resistance to slow down the linear movement. Besides, thedifference of height between the vertical surfaces of the teeth affectsthe smooth actions between the ratchet teeth. The plates and the ratchetblocks cannot be quickly engaged again and the sensitivity of thetransmission is reduced. Besides, the linear movement of the secondexample, the fly wheel h as an annular ratchet gear connected to oneside thereof and this arrangement is difficult to be manufactured theannular ratchet gear is difficult to be machined precisely. Furthermore,there is a gap between the plates and the spring, between the ratchetblock and the permanent magnet, and between the hub and the axle. Thespring or the permanent magnet is simply mounted to the axle and the twoends of the spring or the permanent magnet are not well positioned sothat the parts tend to be inclined or tilt when operation. This affectsthe transmission of the ratchet mechanism.

The present invention intends to provide a hub assembly to mitigate theshortcomings of the conventional hub assemblies.

SUMMARY OF THE INVENTION

The present invention relates to a hub assembly and comprises a hubhaving a first hole defined in one end thereof and an axle extendsthrough the first hole. A first fixing portion is defined in the innerperiphery of the first hole and the first fixing portion is parallel toan axis of the hub. A tubular portion has a second hole in one endthereof and a slot is defined in the inner periphery of the second hole.The slot is parallel to the axis of the tubular portion. A drivingmember is an annular member and has multiple teeth defined in the outerperiphery thereof. The teeth are located corresponding to the slot. Thedriving member has a cone-shaped first ratchet portion formed axiallythereon. The cone-shaped first ratchet portion has two triangularcontact surfaces which form a cone-shaped surface in radial direction.The two triangular contact surfaces have different areas. The teeth ofthe driving member are engaged with the slot and the driving member ismovable linearly in the slot. A passive member is an annular member andhas a second fixing portion which is located corresponding to the firstfixing portion. The passive member has a cone-shaped second ratchetportion formed axially thereon which is engaged with the first ratchetportion. The second fixing portion is fixed to the first fixing portion.A returning member is located between the hub and the passive member.The driving member is movable linearly relative to the tubular portion.The passive member is fixed to the hub so that the linear movement ishappened in only one direction. By the triangular cone-shaped first andsecond ratchet portions, the contact are and the friction between theratchet portions are reduced, and the engagement and disengagement ismore quick and smooth.

The primary object of the present invention is to provide a hubassembly, wherein two ratchet portions are engaged to each other andlocated between a driving member and a passive member. The teeth of eachof the ratchet portions have two triangular contact surfaces in radialdirection so as to reduce contact area and when the driving member andthe passive member are moved linearly and disengaged from each other. Agap is defined between the teeth so that the operation between the tworatchet portions is more sensitive and quick.

Another object of the present invention is to provide a hub assembly,wherein there are first and second fixing portions between the hub andthe passive member so as to be connected to each other. The passivemember is fixed in the hub, cooperated with the linear movement of thedriving member in the tubular portion, the interference to the movementis reduced and the weight of the hub assembly is also reduced.

Yet another object of the present invention is to provide a hubassembly, wherein a tube is connected between the hub, the drivingmember, the passive member and the tubular portion. The tube guides thelinear movement between the driving member, the passive member and thereturning members.

The present invention will become more obvious from the followingdescription when taken in connection with the accompanying drawingswhich show, for purposes of illustration only, a preferred embodiment inaccordance with the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view to show the hub assembly of the presentinvention;

FIG. 2 is an exploded view to show the hub assembly of the presentinvention;

FIG. 3 shows the cross sectional view of the driving member;

FIG. 4 shows the cross sectional view of the passive member;

FIG. 5 shows the cross sectional view of the hub assembly of the presentinvention;

FIG. 6 is an enlarged cross sectional view of the hub assembly of thepresent invention;

FIG. 7 is an enlarged cross sectional view to show the disengagementbetween the teeth of the driving member and the passive member of thehub assembly of the present invention;

FIG. 8 is an exploded view to show the second embodiment of the hubassembly of the present invention;

FIG. 9 shows the cross sectional view of the second embodiment of thehub assembly of the present invention, and

FIG. 10 is an enlarged cross sectional view to show the secondembodiment of the hub assembly of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to FIGS. 1 to 7, the hub assembly of the present inventioncomprises a ratchet mechanism located between a hub 10 and a tubularportion 20, wherein the ratchet mechanism comprises a driving member 30located in the tubular portion 20, a passive member 40 located in thehub 10 and a returning member unit.

The hub 10 is a hollow hub and has a first hole 11 defined in one endthereof and an axle 12 extends through the first hole 11. A first fixingportion 13 is defined in the inner periphery of the first hole 11 andparallel to the axis of the hub 10. The first fixing portion 13 hasinner threads located in the first hole 11.

The tubular portion 20 is a hollow tube and has a second hole 21 in oneend thereof. A slot 22 is defined in the inner periphery of the secondhole 21. The slot 22 is parallel to the axis of the tubular portion 20.The slot 22 comprises multiple notches defined in the inner periphery ofthe second hole 21.

The driving member 30 is an annular member and has multiple teeth 31defined in the outer periphery thereof. The teeth 31 are locatedcorresponding to the slot 22. The driving member 30 has a cone-shapedfirst ratchet portion 32 formed axially thereon and the first ratchetportion 32 comprises multiple cone-shaped notches 33 or protrusions. Inthis embodiment, the first ratchet portion 32 comprises multiplecone-shaped notches 33. Each of the notches 33 in radial direction iscomposed of a first contact surface 34 and a second contact surface 35.Each of the first and second contact surfaces 34, 35 is a triangularsurface. The first contact surface 34 is smaller than the second contactsurface 35. The driving member 30 has a stop 36 which extends axiallyfrom one side thereof which is located away from the first ratchetportion 32. In this embodiment, there are two stops 36. The teeth 31 areengaged with the slot 22 and the first ratchet portion 32 faces the hub10. The driving member 30 is movable linearly in the slot 22.

The passive member 40 is an annular member and has a second fixingportion 41 which is located corresponding to the first fixing portion13. The second fixing portion 41 has outer threads which are locatedcorresponding to the inner threads of the first fixing portion 13. Thepassive member 40 has a cone-shaped second ratchet portion 42 formedaxially thereon and the second ratchet portion 42 is engaged with thefirst ratchet portion 32. The second ratchet portion 42 has multiplecone-shaped protrusion 43 which face the first ratchet portion 32. Eachof the protrusions 43 in radial direction is composed of a third contactsurface 44 and a fourth contact surface 45. Each of the third and fourthcontact surfaces 44, 45 is a triangular surface. The third contactsurface 44 is smaller than the fourth contact surface 45. Theprotrusions 43 each have a triangular cross section in radial direction.The second fixing portion 41 of the passive member 40 is threadedlyconnected to the first fixing portion 13. The second ratchet portion 42faces the tubular portion 20 and is connected to the first ratchetportion 32. The first and third contact surfaces 34, 44 are matched toeach other, and the second and fourth contact surfaces 35, 45 arematched to each other.

The returning member 50 is located between the tubular portion 20 andthe driving member 30. The returning member 50 is a magnet unit whichhas a first magnet 51 and a second magnet 52. The first magnet 51 isconnected to the driving member 30 and located away from the firstratchet portion 32. The second magnet 52 is located in the second hole21 of the tubular portion 20. Two respective facing ends of the firstand second magnets 51, 52 have the same magnetic pole. Cooperated withthe engagement of the first and second ratchet portions, and thereturning member 50, by the magnetically repulsion, the driving member30 rotates toward the passive member 40.

The tube 60 has its inner diameter larger than the diameter of the axle13, the inner diameter of the tube 60 is smaller than the diameter ofthe driving member 30, the passive member 40 and the returning member50. The tube 60 is mounted to the axle 12 located between the hub 10 andthe tubular portion 20, and the tube 60 is located between the axle 12and the driving member 30, and between the passive member 40 and thereturning member 50. The tube 60 guides the linear movement of thedriving member 30 and the returning member 50.

When the tubular portion 20 rotates the driving member 30, the firstcontact surface 34 of the first ratchet portion 32 pushes the thirdcontact surface 44 of the second ratchet portion 42 so as to rotate thehub 10. When the tubular portion 20 rotates in the opposite direction,the second contact surface 35 of the first ratchet portion 32 slidesrelative to the fourth contact surface 45 of the second ratchet portion42, cooperated with the linear movements between the driving member 30and the tubular portion 20, the driving member 30 is disengaged from thepassive member 40 and a gap S is generated due to the linear movement.

As mentioned above, the driving member 30 and the returning member 50are moved linearly in the tubular portion 2. By the engagement betweenthe cone-shaped surfaces of the first and second ratchet portions 32,42, the contact area between the cone-shaped surfaces composed of twotriangular surfaces is reduced and which means less friction isoccurred. The gap S between the driving member 30 and the passive member40 allows the engagement and disengagement to be activated more quicklyand the transmission is more sensitive. The driving member 30 and thepassive member 40 return more quickly. The passive member 40 is fixed tothe hub 10 so that the assembly is easy and the structure is simplified.

When in use, as shown in FIGS. 5 and 6, the first ratchet portion 32 ofthe driving member 30 is engaged with the second ratchet portion 42 ofthe passive member 40, cooperated with the force of the returning member50 and the rotation of the tubular portion 20, the first contact surface34 and the third contact surface 44 are pushed toward each other todrive the hub 10 and transmit torque. When rotation in the oppositedirection as shown in FIG. 7, the second contact surface 35 of the firstratchet portion 32 slides relative to the fourth contact surface 45 ofthe second ratchet portion 42, cooperated with the relative linearmovement between the teeth 31 within the slot 22, the gap S is formedbetween the first and third contact surfaces 34, 44. The driving member30 returns by the force of the returning member 50.

As shown in FIGS. 8 to 10, the second embodiment of the presentinvention is shown and the returning member 50 is a resilient member 53such as a spring. The resilient member 53 is located between the tubularportion 20 and the driving member 30. One end of the resilient member 53is located between the stops 46 of the driving member 40. By the forcefrom the resilient member 53, the driving member 30 moves toward thepassive member 40.

The first and second ratchet portions 32, 42 have notches 33 andprotrusions 43, and each of the notches 33 and the protrusions 43 havecone-shaped portion that is composed by two inclined triangular surfacesso that the contact area is reduced and the friction is also reduced.When rotation in the opposite direction, a gap S is formed between thedriving member 30 and the passive member 40 due to the linear movements,by the force of the returning members 50, the first and second ratchetportions 32, 42 can be engaged again quickly. Furthermore, the first andsecond fixing portions 13, 41 are threadedly connected to each other,cooperated with the linear movement of the driving member 30 in thesecond hole 21 of the tubular portion 20, the one-side movement of thedriving member is not interfered. The structure of the hub assembly issimplified and the weight is reduced.

The tube 60 is mounted to the axle 12 located between the hub 10 and thetubular portion 20, and the tube 60 is located between the axle 12 andthe driving member 30, and between the passive member 40 and thereturning member 50. The tube 60 guides the linear movement of thedriving member 30 and the returning member 50.

The stops 36 of the driving member 30 position the returning member 50to avoid the returning member 50 from tilting off when operation.

While we have shown and described the embodiment in accordance with thepresent invention, it should be clear to those skilled in the art thatfurther embodiments may be made without departing from the scope of thepresent invention.

What is claimed is:
 1. A hub assembly comprising: a hub having a firsthole defined in one end thereof and an axle extending through the firsthole, a first fixing portion defined in an inner periphery of the firsthole and the first fixing portion being parallel to an axis of the hub;a tubular portion having a second hole in one end thereof and a slotdefined in an inner periphery of the second hole, the slot beingparallel to an axis of the tubular portion; an annular driving memberhaving multiple teeth defined in an outer periphery thereof, the teethlocated corresponding to the slot, the driving member having acone-shaped first ratchet portion formed axially thereon, thecone-shaped first ratchet portion having a plurality of first and secondtriangular contact surfaces disposed in a conical arrangement about theaxis of the tubular portion, the first and second triangular contactsurfaces having different areas, the teeth of the driving member engagedwith the slot to maintain the driving member movable linearly in theslot; an annular passive member having a second fixing portion locatedcorresponding to the first fixing portion, the passive member having acone-shaped second ratchet portion formed axially thereon, the secondratchet portion defining a plurality of contact surfaces disposed in acomplementary conical arrangement about the axis of the hub to conicallyengage the first ratchet portion in radially opposed manner, the secondfixing portion being fixed to the first fixing portion, and a returningmember located between the tubular portion and the driving member. 2.The hub assembly as claimed in claim 1, wherein two respective threadedportions are located respectively to the first and second fixingportions so that the first and second fixing portions are connected toeach other.
 3. The hub assembly as claimed in claim 1, wherein the firstratchet portion comprises multiple notches or protrusions and each ofthe notches or protrusions in radial direction comprises a first contactsurface and a second contact surface, each of the first and secondcontact surfaces defining a triangular surface, the first contactsurface being smaller than the second contact surface, the secondratchet portion having multiple cone-shaped protrusions or notchescomplementarily facing the first ratchet portion, each of theprotrusions or notches in radial direction comprising a third contactsurface and a fourth contact surface, each of the third and fourthcontact surfaces defining a triangular surface, the third contactsurface being smaller than the fourth contact surface, the first andsecond ratchet portions being engaged with each other, the first andthird contact surfaces being matched to each other, the second andfourth contact surfaces being matched to each other.
 4. The hub assemblyas claimed in claim 1, wherein the driving member has a stop whichextends axially from one side thereof which is located away from thefirst ratchet portion, the returning member is positioned by the stop.5. The hub assembly as claimed in claim 1, wherein the returning memberis a magnet unit including a first magnet and a second magnet, the firstmagnet being connected to the driving member and located away from thefirst ratchet portion, the second magnet being located in the secondhole of the tubular portion, respective facing ends of the first andsecond magnets being the same in magnetic polarity.
 6. The hub assemblyas claimed in claim 1, wherein the returning member is a resilientmember.
 7. The hub assembly as claimed in claim 1, further comprising atube having an inner diameter larger than a diameter of the axle, theinner diameter of the tube being smaller in diameter than the drivingmember, the passive member and the returning member, the tube beingmounted to the axle and located between the axle and the driving member,and between the passive member and the returning member.